A book that at first seems coy, trite and annoyingly self-referential insidiously turns the reader's expectations around before finally revealing itself as the kind of delicious novel of ideas that a computer-literate Vladimir Nabokov might have written.

The book's protagonist, a novelist in his mid-30s named Richard Powers, returns to his alma mater from abroad after the dissolution of a decade-long love affair. As humanist-in-residence at the Center for the Study of Advanced Sciences, Powers finds himself caught in the middle of a contest between a group of contentious neurologists, one of whom claims to be able to model the human brain by means of computer-based neural networks.

This odd renegade, "lemur-like" Philip Lentz, persuades the author to train a neural net in literary criticism, to feed it the canonical Great Books read by every English lit grad student and then to pass a comprehensive exam. As Lentz puts it, "We can get our supernet to sound exactly like a fashionable twenty-two-year-old North American whiz kid imitating a French theorist in translation by, say, this time next month."

Of course, nothing is that simple. The software proves balky, bogging down in linguistic paradoxes that any normal 3- year-old could navigate with ease. Lentz develops a succession of upgrades, culminating in Implementation H, which mimics a human personality so closely that Powers dubs it "Helen." Meanwhile, Powers broods about the novel he intends to start, dissects his doomed relationship with the woman referred to only as C. and contemplates embarking on a new romance with A., the grad student who will go head-to- head with Helen in the lit-crit challenge.

Anyone familiar with the conventions of postwar science fiction isn't likely to be galvanized at the prospect of another novel that sets itself up as a kind of cybernetic bildungsroman. The implications of machine consciousness have been exhaustively explored by the likes of Isaac Asimov, Robert Heinlein and William Gibson, to name but a few, and Powers, author of the critically acclaimed but mainstream novels "The Goldbug Variations" and "Operation Wandering Soul," seems an unlikely candidate to add anything new to the tradition. In fact, with all its postmodern postur ings, initials-only characters and authorial alter egos, "Galatea 2.2" at first seems to vacillate wildly between the cutesy and the pretentious. It isn't until around Page 100 that you realize Powers is in complete control of the material. He understands linguistics and cognitive neurology on more than just a metaphorical level, and every detail in his richly realized narrative illuminates his theme: the ways language both circumscribes and expands the human experience.

Words are never enough: not for the Powers character, creatively blocked, emotionally wounded, tongue-tied when trying to converse while living with C. in the Netherlands; not for his colleague's retarded child; not for Lentz's wife, caught in the grip of Alzheimer's; not for Helen, ultimately stunned into silence by the atrocities humankind visits upon itself. But language is all they have to make sense of the world and their lives. Powers quotes a line from Psalms: "We spend our years as a tale that is told. . . . And the tale that we tell is of the years we spend."

The tale Powers tells in "Galatea 2.2." offers the reader tantalizing challenges and deep rewards. With dazzling stylistic virtuosity and a keen grasp of character, Powers has reshaped the myth of Pygmalion into a compelling parable for the digital age.